package com.cloudshop.service.user.controller;

import com.cloudshop.service.user.utils.ResourceUtil;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;
import java.util.concurrent.TimeUnit;
import javax.annotation.Resource;
import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.ValueOperations;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;

/**
 * 生成验证码.
 *
 * @author 宫新程
 */
@Controller
public class VerificationCodeController {

  @Resource private StringRedisTemplate stringRedisTemplate;

  static {
    System.setProperty("java.awt.headless", "true");
  }

  /** 干扰线 */
  private static final int count = 200;
  /** 定义图形大小(宽) */
  private static final int width = 105;
  /** 定义图形大小(高) */
  private static final int height = 35;
  /** 干扰线的长度=1.414*lineWidth */
  private static final int lineWidth = 1;

  /**
   * 生成验证码
   *
   * @param request
   * @param response
   * @throws ServletException
   * @throws IOException
   */
  @RequestMapping(
      value = "/generate",
      method = {RequestMethod.POST, RequestMethod.GET})
  public void VerificationCode(
      @RequestParam("yzmRedisKey") String yzmRedisKey,
      HttpServletRequest request,
      HttpServletResponse response)
      throws Exception {

    // 设置页面不缓存
    response.setHeader("Pragma", "No-cache");
    response.setHeader("Cache-Control", "no-cache");
    response.setDateHeader("Expires", 0);

    // 在内存中创建图象
    final BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
    // 获取图形上下文
    final Graphics2D graphics = (Graphics2D) image.getGraphics();

    // 设定背景颜色
    graphics.setColor(Color.WHITE); // ---1.Color.WHITE为白色
    graphics.fillRect(0, 0, width, height); // 填充衍射
    // 设定边框颜色
    // ---2.这是以数字型来设置颜色，颜色模式是指使用三种基色：红、绿、蓝，通过三种颜色的调整得出其它各种颜色，这三种基色的值范围为0～255
    graphics.drawRect(0, 0, width - 1, height - 1);

    final Random random = new Random();
    // 随机产生干扰线，使图象中的认证码不易被其它程序探测到
    for (int i = 0; i < count; i++) {
      graphics.setColor(getRandColor(150, 200)); // ---3.

      final int x = random.nextInt(width - lineWidth - 1) + 1; // 保证画在边框之内
      final int y = random.nextInt(height - lineWidth - 1) + 1;
      final int xl = random.nextInt(lineWidth);
      final int yl = random.nextInt(lineWidth);
      graphics.drawLine(x, y, x + xl, y + yl);
    }

    // 取随机产生的认证码(4位数字)
    final String resultCode = exctractRandCode();
    for (int i = 0; i < resultCode.length(); i++) {
      // 设置字体颜色
      graphics.setColor(Color.BLACK);
      // 设置字体样式
      graphics.setFont(new Font("Times New Roman", Font.BOLD, 24));
      // 设置字符，字符间距，上边距
      System.out.print(resultCode.charAt(i));
      graphics.drawString(String.valueOf(resultCode.charAt(i)), (23 * i) + 8, 26);
    }

    System.out.println("直接输出：" + resultCode);

    // 将验证码放入Redis中，别设置过期时间
    ValueOperations<String, String> operations = stringRedisTemplate.opsForValue();
    operations.set(yzmRedisKey, resultCode, 5, TimeUnit.MINUTES);

    // 图象生效
    graphics.dispose();

    // 输出图象到页面
    ImageIO.write(image, "JPEG", response.getOutputStream());
  }

  /** 随机码. */
  private String exctractRandCode() {
    final String randCodeType = ResourceUtil.getRandCodeType();
    int randCodeLength = Integer.parseInt(ResourceUtil.getRandCodeLength());
    if (randCodeType == null) {
      return RandCodeImageEnum.NUMBER_CHAR.generateStr(randCodeLength);
    } else {
      switch (randCodeType.charAt(0)) {
        case '1':
          return RandCodeImageEnum.NUMBER_CHAR.generateStr(randCodeLength);
        case '2':
          return RandCodeImageEnum.LOWER_CHAR.generateStr(randCodeLength);
        case '3':
          return RandCodeImageEnum.UPPER_CHAR.generateStr(randCodeLength);
        case '4':
          return RandCodeImageEnum.LETTER_CHAR.generateStr(randCodeLength);
        case '5':
          return RandCodeImageEnum.ALL_CHAR.generateStr(randCodeLength);
        default:
          return RandCodeImageEnum.NUMBER_CHAR.generateStr(randCodeLength);
      }
    }
  }

  /**
   * 描述：根据给定的数字生成不同的颜色.
   *
   * @param fc 这是以数字型来设置颜色，颜色模式是指使用三种基色：红、绿、蓝，通过三种颜色的调整得出其它各种颜色，这三种基色的值范围为0～255
   * @param bc 这是以数字型来设置颜色，颜色模式是指使用三种基色：红、绿、蓝，通过三种颜色的调整得出其它各种颜色，这三种基色的值范围为0～255
   * @return 描述：返回颜色
   */
  private Color getRandColor(int fc, int bc) { // 取得给定范围随机颜色
    final Random random = new Random();
    if (fc > 255) {
      fc = 255;
    }
    if (bc > 255) {
      bc = 255;
    }

    final int r = fc + random.nextInt(bc - fc);
    final int g = fc + random.nextInt(bc - fc);
    final int b = fc + random.nextInt(bc - fc);

    return new Color(r, g, b);
  }

  /** 验证码辅助类 */
  enum RandCodeImageEnum {
    /** 混合字符串 去除小写的l和o这个两个不容易区分的字符； */
    ALL_CHAR("0123456789abcdefghijkmnpqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"),
    /** 字符 */
    LETTER_CHAR("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"),

    /** 小写字母 */
    LOWER_CHAR("abcdefghijklmnopqrstuvwxyz"),

    /** 数字 */
    NUMBER_CHAR("0123456789"),
    /** 大写字符 */
    UPPER_CHAR("ABCDEFGHIJKLMNOPQRSTUVWXYZ");
    /** 待生成的字符串 */
    private String charStr;

    /** @param charStr */
    private RandCodeImageEnum(final String charStr) {
      this.charStr = charStr;
    }

    /**
     * 生产随机验证码
     *
     * @param codeLength 验证码的长度
     * @return 验证码
     */
    public String generateStr(final int codeLength) {
      final StringBuffer sb = new StringBuffer();
      final Random random = new Random();
      final String sourseStr = getCharStr();

      for (int i = 0; i < codeLength; i++) {
        sb.append(sourseStr.charAt(random.nextInt(sourseStr.length())));
      }

      return sb.toString();
    }

    /** @return the {@link #charStr} */
    public String getCharStr() {
      return charStr;
    }
  }
}
